1. Field of the Invention
The present invention relates to a focus adjustment device and a focus adjustment method.
2. Description of the Related Art
As an automatic focus adjustment technique for an imaging lens provided in an imaging device, a contrast AF method is used. The contrast AF method is a method to adjust the focus of a focus lens on the basis of an evaluation value calculated from an image signal generated in accordance with a light flux received by an imager via an imaging lens. In the contrast AF method, for example, wobbling drive is performed to judge the drive direction of the focus lens to be in focus. The wobbling drive is a technique to judge the drive direction of the focus lens to be in focus by slightly driving the focus lens in a near direction and a far direction and comparing evaluation values in the driving in the near direction and the driving in the far direction.
Meanwhile, in the contrast AF method, there is a possibility that the focus lens may be focused on a subject different from a desired subject in a scene where subjects are mixed far and near. For example, Jpn. Pat. Appln. KOKAI Publication No. 2010-107578 and Jpn. Pat. Appln. KOKAI Publication No. 2007-178480 suggest techniques to enable suitable focus adjustment even in a scene where subjects are mixed far and near.